The goal of this proposal is to determine the mechanisms that mediate the extensive reactivations of somatosensory cortex and the return of hand use after large lesions of cutaneous receptor afferents in the dorsal columns of the spinal cord. Our experiments will determine if new connections are formed in the post- lesion somatosensory system, if a promising treatment with an enzyme promotes useful new connections, and if reactivated neurons in somatosensory cortex have response properties to touch on the hand that would usefully guide tactile behavior.